Some elevators are driven by a motor having a geared speed reducer attached thereto. The motor rotor rotates at a relatively fast first speed and either is or directly interacts with an input axle. The input axle is attached to a pinion-ring gear mechanism, or worm gear/ring gear mechanism, or other speed reducer, to an output axle that carries a drive sheave. The drive sheave supports and provides motive force to elevator suspension cables. The output axle usually rotates at a relatively slower second speed.
At present, the output axle carrying the sheave has three supports; one at either end thereof and one at a central point. These supports encounter expensive and complex on-site adjustment problems which if not satisfactorily resolved cause material fatigue.
Utilizing a sectioned output axle to avoid misalignment is not a good solution because it requires an oversized Cardan or other universal joint; moreover, vibration and noise problems would arise.
Eliminating the central support may cause the formation of large flexions which should also have vibration, noise and fatigue problems.